PATENTS

FIFTEEN-PHASE AUTOTRANSFORMER

Issued: May 18, 2010

United States Patent 7,719,858

A polygon connected three-phase autotransformer using nine windings per phase provides a reduced power rating fifteen-phase power source suitable for 30-pulse AC to DC power converters. The windings are selected and connected in a manner that accommodates zero-sequence currents, such as the third harmonic, and minimizes total kVA rating. When the autotransformer is used to power a 15-phase AC to DC converter, its kVA rating is typically less than 51% of the DC load kW. AC line current distortion is negligible and can satisfy the most exacting practical harmonic specifications.

Inventors: Paice; Derek Albert (Palm Harbor, FL)

Appl. No.: 12/387,440

Filed: May 4, 2009

DISCONTINUOUS CONDUCTION MODE (DCM) USING SENSED CURRENT FOR A SWITCH-MODE CONVERTER

Issued: May 18, 2010

United States Patent 7,719,248

A switch-mode converter controller and method utilizes a comparator for receiving and comparing a sensed current and a peak current that is determined by a product of a multiplying factor, that is greater than or equal to two, and a target current. A finite state machine (FSM) is configured to operate the switch-mode converter in a discontinuous conduction mode (DCM). Responsive to the comparator, the FSM turns on the switch and observes an on-time duration of the switch until the sensed current reaches the peak current; calculates a switching period responsive to the peak current and the observed on-time duration; and varies the switching period responsive to the on-time duration and the multiplying factor such that an average of the sensed current equals the target current.

Inventors: Melanson; John Laurence (Austin, TX)

Assignee: Cirrus Logic, Inc. (Austin, TX)

Appl. No.: 12/110,714

Filed: April 28, 2008

POWER CONTROL SYSTEM USING A NONLINEAR DELTA-SIGMA MODULATOR WITH POWER CONVERSION MODELING

Issued: May 18, 2010

United States Patent 7,719,246

A power control system includes a switching power converter and a power factor correction (PFC) and output voltage controller. The switching power converter utilizes a nonlinear energy transfer process to provide power to a load. The PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. The PFC and output voltage controller includes a nonlinear delta-sigma modulator that models the nonlinear energy transfer process of the switching power converter. The nonlinear delta-sigma modulator generates an output signal used to determine the control signal. By using the nonlinear delta-sigma modulator in a control signal generation process, the PFC and output voltage controller generates a spectrally noise shaped control signal.

Inventors: Melanson; John L. (Austin, TX)

Assignee: Cirrus Logic, Inc. (Austin, TX)

Appl. No.: 11/967,269

Filed: December 31, 2007

DC-DC SWITCHING CONVERTER DEVICE

Issued: May 18, 2010

United States Patent 7,719,137

A DC-DC switching converter device, in particular a quarter-brick or eighth-brick device having an industry standard pin out, comprises a pulse-width modulation circuit for driving a power converting switch, a trim connector for adjusting an output voltage of the device, where the device is designed such that the pulse-width modulation circuit is synchronizable to an external oscillator by an external synchronization signal applied to the trim connector. A DC-DC converting circuit comprises a plurality of DC-DC switching converters featuring trim connectors for adjusting output voltages of the converters, whereby the converters are connected such that they share a common input bus. It further features a system EMI (electromagnetic interference) filter common to all the DC-DC switching converters and an external oscillator delivering an external synchronization signal to the plurality of DC-DC switching converters.

METHOD TO SET A REFERENCE POTENTIAL OF A CURRENT SENSOR IN A POWER SEMICONDUCTOR DEVICE

Issued: May 18, 2010

United States Patent 7,719,254

A method for setting a reference potential of a current sensor in a power semiconductor device is disclosed. On the basis of a specific geometry and a typical two-dimensional potential distribution of the power semiconductor device, a plurality of tapping points is predetermined on an area of the power semiconductor device. On the basis of the specific geometry of the power semiconductor device, a line course between the tapping points and a measuring point for measuring a potential average value is determined and realized. Respective potential values are detected at the tapping points and fed to the measuring point. The potential average value is determined at the measuring point. The potential of the current sensor is set to the potential average value thus determined.

TWO-SOURCE SERIES INVERTER

Issued: May 18, 2010

United States Patent 7,719,138

Systems and methods are disclosed for a two-source series inverter. The systems and methods combine operation of a first voltage source and a second voltage source in series powering a novel voltage combining arrangement and a conventional inverter via a switch configuration to power a load. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.